Mary was untouched by man when she met Joseph. One night Mary was visited by an angel. She was touched in a way that is hard for us all to believe. But believe we must....Miracles happen every day of our lives and we usually don't acknowledge the one who makes these miracles happen.
Joseph was also visited by an angel, his visitor told him a wonderful story of how his beloved Mary was with child and the child would be the "Savior" to the whole world. This was a bit of news hard to swallow for Joseph. His beliefs were very strong and he loved Mary so much. He trusted God and knew that his visit was a direct message from above. So they were married and started their journey to Bethlehem to pay their yearly taxes.